Calcium salt of the organic phosphorus compound contained in milk casein and processof making the same



Patented Sept. 29, 1925.

UNITED STATES PATENT OFFICE.

SWIGEiI POSTER-NAB; OF CEENE-BOUG-ERIES, NEAR GENEVA, SWITZERLAND, .AS-

SIGNOR TOTEE SOCIETY OF CHEMICAL INDUSTRY IN BASLE, OF BASED, SWITZER- LAND.

CALCIUM saw THE ORGANIC PHOSPHORUS COMPOUND CONTAINED IN MILK CASEI'AI' AND PROCESS OF MAKING THE SAME.

No Drawing.

' To all whom it may concern:

Be it known that I, SWIGEL POSTERNAK, a citizen of Switzerland, residing. at Chene- Bougeries, near Geneva, in the Confedera tion of. Switzerland, have invented a new and useful Calcium Salt of the Organic Phosphorus Compound Contained in Milk Casein and Processes of Makin the Same, of which the following is a ful clear, and exact specification.

The only attempt to render available for technical use the organic phosphorus compound contained in milk casein is due to Salkowski (D. R. P. Kl. 114,273) who after neutralizing a solution made by digestion of the casein with pepsin and hydrochloric acid evaporates it to one half, then mixes with a solution of iron ammonium sulfate (iron ammonium alum), and, finally, coagulates the mixture by heating. In this manner he obtains an iron compound which still richer in is insoluble in water, containing on an average 2.5 per cent of phosphorus .and 22 per cent of iron.

By treatment with warm caustic soda solution the iron compound is freed from the iron, and then precipitated with copper acetate, the precipitate is freed from cop er with hydrogen sulfide, and the solution t us obtained after appropriate concentration is precipitated by alcohol. The white precipitate contains 4.05 per cent of phosphorus and is supposed to represent the free organic phosphorus com ound.

It is obvious that, i the" latter compound constitutes the free acid of the original iron salt, it is to be supposed that this salt contains at least 25 per cent of foreign impurities. The production of a compound richer in phosphorus is complicated and connected with great losses.

It has now been found that reparations phosphorus than t e aforesaid white precipitate can be obtained in a very sim le manner by digesting the milk casein wit trypsin in wea ammoniacal solution and separating the organic phosphorus compound from the solution in the form of a compound of an alkaline-earth metal and especially as a calcium compound soluble in water, which is excellently suitable for therapeutic utilization.

The process is based on the following ob- Application filed July 20, 1923. Serial No. 652,851.

servations. In weak ammoniacal solution the milk casein-is split by trypsin ina veryshort time, so that the organic phosphorus corplpound in question is liberated.

e ammomacal liquid produced by the,

try sin digestionyields a precipitate neither wit a salt of an alkaline-earth metal nor with one to two volumesof alcohol. If, however, there is added first a suitable quantity of a salt of alkaline-earth metals and then one volume of alcohol, a precipitate is obtained which consists, in greater part, of the organic phosphorus compound in the form of a compound of the alkaline-earth 'metal. The precipitate is soluble in water and can be purified by re-precipitation with one volume of alcohol! Preliminary to the precipitation of the calcium salt the phosphorus compound may be purified by conversion into an insoluble heavy metal salt. For instance, the solution produced by the trypsin digestion, after separation from the solid matter by pressing, maybe treated with lead acetate, the

precipitate thus produced may be deprived of lead in a suitable manner, for instance by means of hydrogen sulfide, the acid filtrate neutralized with milk of lime and the calcium salt directly precipitated by alcohol or A the filtrate may be neutralized with ammonia and the solution thus obtained treated, in the above-described manner, to obtain the calcium salt.

The invention is illustrated by the following examples. I

' Example 1.

contained in the casein separate in form of.

flocks which may easily be filtered. This stage of the process is usually attained in about 48 hours. The mass is left at rest in the cold for another 24 hours, after which there are added 500 grams of diatomaceous earth, while stirring, whereupon the mixture is filter-pressed. To the clear filtrate there is added a concentrated solution of 300 grams of calcium chloride or 430 grams of calcium acetate and 85 liters of alcohol. After two hours the precipitate is filtered, washed with dilute alcohol, dissolved in 2 liters of water and precipitated again with the same volume of alcohol. Finally the precipitate is washedvwith alcohol, filterpressed, dried in the vacuum, and pulverized. Y

In this manner there are obtained about 1.25 kilos of a white powder easily soluble in water having'an indiiierent taste and containing 4.5 to 5 per cent of phosphorus, 10 to 11 per cent of calcium and about 11.5 per cent of nitrogen.

Example 2.

10 kilos of commercial milk casein are treated with ammonia and trypsin, as described in the preceding exam 1e, in 80 liters of Water previously warme to 40 C. After filter-pressing an aqueous solution of basic lead acetate is added to the liquid until no further precipitate is formed; an excess must, however, be avoided as thereby the precipitate would in part be re-dissolved. For the precipitation there are required about 5 liters of lead acetate. The lead precipitate 1s filtered, thoroughly washed with hot water, deprived of the lead by meansof hydrogen sulfide, and liberated from the, excess of the hydrogen sulfide by an air current. Then ammonia is added until the liquid is alkaline to phenolphthalein, whereupon the phosphorus compound is precipitated with 400 grams of a concentrated solution of calcium acetate and a volume of alcohol equal to that of the liquid. The precipitate is further worked up as indicated in the preceding example.

It may be remarked that, without altering the result in any way, the precipitation may also be effected with-other salts of lead, for instance, sugar of lead in presence of an excess of ammonia, or with salts ing to usual methods, with trypsin in a weak ammoniacal solution until separation of the fatty acids, originating from the fat of the casein, occurs, precipitating the filtered digestion liquid with a soluble calcium salt and about one volume of alcohol, redissolving the precipitate of the calcium salt of the phosphorus compound thus obtained in water, reprecipltating the solution with alecho], and drying the product thus purified.

2. The herein described process for the manufacture of the calcium salt of the organic phosphorus com und contained in milk casein, by precipitating the solution resulting from the trypsin digestion of casein with soluble calcium salts and alcohol.

3. The herein described process for the manufacture of the calcium salt of the organic phosphorus compound containe in milk casein, by precipitating the solution resulting from the trypsin digestion of casein with'soluble calcium salts and alcohol, redissolving the precipitate thus formed in water, and reprecipitating the solution with alcohol.

4. As new roduct the herein described calcium salt oFth'e organic phosphorus compound contained in milk casein, constituting a white powder of indifferent taste easily soluble in water and containing 4.5 to 5 per cent of phosphorus, 10 to 11 per cent of calcium, and about 11.5 per cent of nitrogen.

In witness whereof I have hereunto signed my name this 5th day of July 1923.

' SWIGEL POSTERNAK. 

